The present invention relates generally to data communication and control, and, more particularly, to devices, systems and methods for communication of data and control based thereon in contrast-enhanced medical imaging systems.
It is well recognized that the appropriate dose for many medications is related to a number of variables, including, for example, the size, weight, or physiologic state of the patient being treated. This variation is readily apparent from the different recommended doses many medications have for adults and children. The appropriate dose of contrast media for a given medical imaging procedure is equally dependent upon the size and weight of the patient being examined as well as additional factors.
Although differences in dosing requirements for medical imaging procedures have been recognized, many conventional medical imaging procedures, including angiographic, computed tomography, magnetic resonance and ultrasound imaging, continue to use pre-set doses or standard delivery protocols for injecting contrast media during medical imaging procedures. Although using fixed protocols for delivery simplifies the procedure, providing the same amount of contrast media to patients of widely varying size and weight can produce very different results in image contrast and quality.
Some of the shortcomings of existing procedures have been addressed and resolved as described in U.S. Pat. No. 5,806,519, issued Sep. 15, 1998, the disclosure of which is incorporated herein by reference. U.S. Pat. No. 5,806,519 discloses a contrast media delivery system that provides a source of contrast media sufficiently isolated from a patient undergoing an imaging procedure that the source of contrast media may be used on additional patients without concern for contamination. Additionally, the system is capable of adjusting contrast media concentration and other injection parameters during an injection procedure. The term xe2x80x9cconcentrationxe2x80x9d refers generally to the concentration of the image enhancing agents, particles or chemicals, in the contrast media.
The system of U.S. Pat. No. 5,806,519 incorporates a source of contrast media and, if desired, an admixture to dilute the media. If there is an admixture, then the contrast media preferably has a concentration which is the highest that would be used in an injection procedure so that the operator may combine the contrast media with the admixture and select virtually any concentration of contrast media desired for any given procedure. The concentration of the contrast media injected into a patient may be varied during the injection procedure by varying the ratio of admixture to contrast media. Each patient thus receives only the amount of contrast media necessary to provide a proper diagnostic image.
It has been recognized that the system of U.S. Pat. No 5,806,519 is much more versatile and useful if the operator is able to select and adjust contrast media concentration and other injection parameters based on patient information and/or feedback received during the injection imaging procedures. U.S. patent application Ser. No. 09/197,773 and U.S. Pat. No. 5,840,026 disclose such systems. Those systems are capable of automatically choosing the appropriate concentration and injection rate for a given patient and are capable of automatically adjusting concentration and other injection parameters during an injection procedure based on feedback related to the resultant image quality.
Although significant strides have thus been achieved in the control of contrast-enhanced, medical imaging procedures, it remains desirable to develop improved devices, systems and methods for communication of data between devices and control based thereon in contrast-enhanced medical imaging systems.
The present invention provides several systems, devices and methods for producing a contrast-enhanced medical image of a patient. According to one embodiment, such a system includes generally a source of a contrast or enhancement medium and a pressurizing unit in connection with the source of contrast or enhancement medium to pressurize the contrast or enhancement medium for injection into the patient. The contrast medium or enhancement medium is also called the fluid medium, being a liquid, gas, or solid suspended in a liquid or a gas. The system also includes an energy source adapted to apply energy to a region of the patient and an imaging unit providing (preferably in real-time) an indication (for example, a visual or audible indication) of an internal state, condition or view of the patient based upon a signal resulting from the energy applied to the region of the patient. This signal is affected by a condition of the contrast or enhancement medium in the patient. The system also includes a control unit adapted to adjust the condition of the contrast or enhancement medium in the patient based upon the signal resulting from the energy applied to the region of the patient. The system may include general components or pieces of equipment manufactured by more than one company, for instance, an injector and an imager.
The condition of the fluid medium flowing into the patient can, for example, correspond to at least one parameter including, but not limited to, contrast medium concentration, flow rate of the contrast medium, timing of an injection, sequencing of more than one injection (of the same or different contrast media), injected volume of the contrast medium, injection pressure of the contrast medium or temperature of the contrast medium.
Although U.S. Pat. No. 5,840,026 describes generally the use of the pixel intensity of one or more portions or regions of the visual display of an imaging unit to control one or more conditions of the fluid medium within the patient, the present inventors have also discovered that direct use or modification of the raw signal used to produce the image may have certain significant advantages in controlling the imaging procedure. For example, a portion of the information available from the raw signal may be lost or distorted in various compression algorithms that are used to address the limited dynamic range of the displays that are available to show an image. The energy applied to the region of the patient may, for example, be sonic energy, in which case the raw signal is an acoustic intensity signal. This particular method is sometimes called acoustic intensitometry or acoustic densitometry. The energy may, for example, also be penetrating radiation such as X-rays, or non-ionizing electromagnetic radiation such as light.
The present invention also provides another embodiment of a system for producing a contrast-enhanced medical image of a patient including a source of a fluid medium and a pressurizing unit as described above. As used herein, the terms xe2x80x9cimagexe2x80x9d or xe2x80x9cviewxe2x80x9d refer generally to an indication of an internal condition or state of a patient and are not limited to a visual display. The system also includes an energy source and an imaging unit to provide (preferably in real-time) an indication (for example, a visual display) of an internal view of the patient based upon a signal resulting from the energy applied to the region of the patient. In this embodiment, the system further includes a control unit adapted to adjust the condition (as described above) of the fluid medium in the patient to maintain at least one portion of the indication (for example, a portion of a visual display) at a desired level of intensity or enhancement. For example, the control unit can adjust the condition of the fluid medium flowing into the patient based upon the signal resulting from the imaging energy applied to the region of the patient. The system can also adjust the condition of the fluid medium flowing into the patient based upon measured intensity or density of the portion of a visual display. Such control of the imaging procedure assists in the study of, for example, lesions in the region of interest.
In another embodiment, the control unit adjusts parameters of the imaging unit to obtain an optimum or sufficient image based upon the concentration of the contrast enhancing agent flowing into the patient. Possible adjusted parameters include but are not limited to: the power in the signal sent into the patient, the time during which the energy is applied to the patient, the gain of the amplifier which receives the signal from the patient, or the speed at which the energy is scanned across the patient.
The present invention also provides a system for delivering an active substance (for example, a biologically active therapeutic substance or a diagnostic substance) to a patient including a source of a fluid medium that incorporates the active substance and a contrast agent. A pressurizing unit is in fluid connection with the source of fluid medium to pressurize the fluid medium for injection into the patient. The system also includes an imaging energy source adapted to apply imaging energy to a region of the patient and an imaging unit providing a visual display (preferably in real-time) of an internal view of the patient based upon a signal resulting from the imaging energy applied to the region of the patient. The system further includes a control unit adapted to control delivery of the active substance by adjusting the condition of the contrast agent in the patient.
In this embodiment, the active substance is preferably activated by activation energy from a source of activation energy. The activation energy and the imaging energy can be the same or different types of energy. In general, the concentration of the active substance in a region of interest will be directly proportional to the concentration or amount of contrast agent in the region of interest. The strength and duration of the applied activation energy can, for example, be adjusted based upon the signal resulting from the imaging energy or upon the resulting visual or other (for instance sound pitch, sound volume, numeric readout, or meter readout) indication provided to the user (preferably in real-time). The contrast medium and the active substance may be combined. For example, a therapeutic drug or a gene therapy may be contained in partially gas filled microspheres that are ruptured by ultrasound energy beamed into a specific part of the body to activate the therapeutic drug or gene therapy.
The present invention further provides another system for producing a contrast-enhanced medical image of a patient similar to the systems described above. In this embodiment, however, the control unit is adapted to time injection of at least one discrete flow interval of fluid medium based, for example, upon at least one of a visual display or a signal resulting from application of the imaging energy to a region of the patient (both may be used simultaneously). In one embodiment, the discrete flow interval may be a bolus of fluid medium.
Preferably, unidirectional or bi-directional communication and optionally control between devices of the present invention is enabled through use of a control/communication interface to which each of the devices of the imaging/injection system can be connected. This interface mating point can be located on a separate device or can be incorporated into one of the other devices (for example, into a controller for the pressurizing unit or injector). Suitable communication methods include data transmission, preferably digital, over wires, fiber optics, or via conducted or broadcast electromagnetic radiation (for example light and RF) or ultrasonic radiation.
The communication interface of the present invention is a substantial improvement over previous systems that merely communicated timing information via relay closures. In the present invention, data transmission includes information sent between devices regarding operating parameters, operator input, device status information, and/or control sequencing. In addition, data transferred from one device to another device in the present invention can be used to enable active control of the receiving device from that data. For example, during the injecting state, data transmission from an ultrasound imager can be sent to an injector to enable active control of the injection flow rate based on the data received. Currently available systems merely relay analog closures between an injector and an imager to communicate the timing of certain states and are not used for data transmission or communication. In such systems, the relay closure causes the injector or imager subsystem to begin executing a preset program. In the present invention on the other hand, data on the status of one subsystem is communicated to the other subsystem for use by that subsystem. The receiving subsystem may alter its operation based upon this information, even to the extent of being programmed by the transmitting subsystem. Moreover, digital communication enabled by the present invention allows much more information to be conveyed than a simple relay closure.
Preferably the communicating devices use the same protocol so that the information being communicated does not need to be converted. Note that it is also possible for the devices to support multiple communication protocols which may be selected by the user or selected by automatic negotiation between the communicating devices.
In addition, the present invention provides methods for adjusting the condition of a fluid medium (as described above) during an imaging procedure. In one embodiment, the method includes pressurizing the fluid medium for injection into the patient. Further, the method includes supplying energy to a region of the patient and indicating (preferably in real-time) an internal view (that is, a condition or state) of the patient based upon a signal resulting from the energy applied to the region of the patient. This signal is affected by a condition of the fluid medium in the patient as described above. The method further comprises the step of adjusting the condition of the fluid medium in the patient based upon the signal resulting from the energy applied to the region of the patient.
In another method, the condition of the fluid in the patient is adjusted to maintain at least one portion of the indication (for example, a portion of a visual display) at a desired level of intensity/density or intensity/density profile over time. For example, the control unit can adjust the condition of the fluid medium in the patient based upon the signal resulting from the energy applied to the region of the patient to provide enhancement in the region of interest that is constant or varies within some acceptable range. The system can also adjust the condition of the fluid in the patient based upon measured intensity of the portion of a visual display or measured intensity of an acoustic indicator. As discussed above, such control of the imaging procedure can assist, for example, in the study of lesions in the region of interest.
The present invention also provides a method for delivering an active substance to a patient, comprising the step of controlling delivery or administration of the active substance by adjusting the condition of the contrast agent in the patient. As described above, the active substance is preferably activated by activation energy from a source of activation energy. The activation energy and the imaging energy can be the same or different types of energy.
The present invention also provides for structured communications in the situation where the control unit functions are shared between two or more pieces of equipment.
For example, the present invention provides a system for control of an imaging procedure comprising: a source of a contrast or enhancement medium; a pressurizing unit in fluid connection with the source of contrast or enhancement medium to pressurize the contrast or enhancement medium for injection of the contrast or enhancement medium into the patient; an imaging energy source adapted to apply imaging energy to a region of the patient; an imaging unit providing an indication (for example, a visual display) of an internal view of the patient based upon a signal resulting from the imaging energy applied to the region of the patient, the signal being affected by a condition of the contrast or enhancement medium in the patient; and a data communication interface between at least the pressurizing unit and the imaging unit to enable exchange of data between the pressurizing unit and the imaging unit. Preferably, the exchange of data is bi-directional. Moreover, the data is preferably in digital form.
The present invention also provides an injector system for producing a contrast-enhanced medical image of a patient in cooperation with an imaging system. As described above, the imaging system applies energy to a patient and produces an image or a measurement of a region of interest in the patient from a signal resulting from the applied energy. The injector system preferably comprises: a source of a contrast or enhancement medium; a pressurizing subsystem in connection with the source of contrast or enhancement medium to pressurize the contrast or enhancement medium for injection into the patient; an injector control unit for controlling said pressurizing subsystem; and a communication interface to exchange data between the injector system and the imaging system.
The injector system may communicate information from the injector system to the imaging system. Likewise, the imaging system may communicate data or information from the imaging system to the injector system. Such communication can be unidirectional or bi-directional. The injector control unit may modify one or more parameters of the injection based upon the data or information from the imaging system. The imaging control unit may also modify one or more parameters of the imager unit based on the data or information sent from the injector. The injector system may further contain an electrically and/or physically isolated (wireless) interface through which the communication interface exchanges data or information with the imaging unit.
The present invention also provides an imaging unit for producing a contrast-enhanced medical image of a patient in cooperation with an injector system. As described above, the injector system pressurizes a contrast or enhancement medium for injection into the patient. The imaging unit preferably comprises: a source of energy to be applied to a region of interest in the patient; a display to provide an image based upon a signal resulting from the imaging energy applied to the region of the patient; an imaging control unit for controlling the imaging unit; and a communication interface to exchange data or information between the injector system and the imaging unit.
Communication of data/control may be from the injector system to the imaging unit or visa versa and either uni- or bi-directional. The imaging unit preferably further contains an electrically and/or physically isolated interface through which the communication interface shares information with the injector system.
The interface is preferably in communicative connection with at least the pressurizing unit and the imaging unit to enable sharing and exchanging of data between the pressurizing unit and the imaging unit.
The above and other systems, devices and methods of the present invention, and their attendant advantages, will become even more apparent to one skilled in the art upon consideration of the following detailed description in combination with the accompanying drawings.